对于抗震设计规范设计反应谱的探讨和建议

Discussions and Suggestions about the Design Response Spectrum of Seismic Design Code

随着长周期的高层结构和大阻尼的消能减振结构应用的增多,提出适用于此类结构的抗震设计反应谱的重要性逐渐提升。本文对真伪反应谱进行了对比分析,指出伪绝对加速度谱能够代表结构弹性内力,真绝对加速度谱不能代表结构弹性内力且存在反超现象,对真伪反应谱之间的关系做了定量分析。利用简谐荷载双规准谱分析了地震反应谱的一般规律。建议规范设计反应谱采用伪加速度谱或与之等效的三联谱,指出了三联谱间的等效关系以及反应谱转折点周期与三联谱峰值间的关系,并对该谱的相关特征受阻尼比和地震动特性的影响进行了研究和讨论。

With the increasing construction of long-period high-rise structures and the application of energy dissipation devices with large damping,the applicable seismic design response spectrum should be proposed In this paper,the true and pseudo response spectrum is analyzed.It is pointed out that the pseudo absolute acceleration spectrum can represent the elastic internal force of the structure,while the true absolute acceleration spectrum can not,in which there exists an overtaken phenomenon.And the relationship between true and false response spectra was analyzed quantitatively.The general law of the seismic response spectrum is analyzed by using the bi-normalized spectrum of simple harmonic load.It is suggested that the pseudo acceleration spectrum or equivalent triple spectrum should be used in the design response spectrum.The equivalent relationship between the triple spectrum and the relationship between the turning point period of the response spectrum and the peak value of the triple spectrum are pointed out.The influence of damping ratio and ground motion characteristics on the relevant characteristics of the spectrum is studied and discussed.